Bridge for supporting electric fixtures.



J. R. GUNN,

BRIDGE FOR SUPPORTING ELECTRIC FIXTURES.

APPLICATION FILED JUNE 7. 19l5- 2 SHEETSrSHEET I.

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BRIDGE FOR SUPPORTING ELECTRIC FIXTURES.

APPLICATION FILED M151, 1915.

Patented Jan. 30, 1%.

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JOHN ]R.. GUN'N, OF DETRGIT, MICHIGAN.

Application filed June 7, 1915.

To all whom it may concern:

Be it known that 1, JOHN R. GUNN, a cit1- zen of the United States, residing at De- I troit, county of Wayne, State 01": Michigan, have invented a certain new and useful llmprovement in Bridges for Supporting Electric Fixtures, and declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which-it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to a bridge for supporting outlet boxes from joists or studs and has for its object a bridge which may accommodate itself to the varying spaces that are found between joists and studs.

In the drawings d igure 1 is a top plan view of the adjustable bridge used to support the ceiling box and an electric lamp fixture. line illd of l ig. l. cross section on the line G@ of Fig. 1. Fig. 4: is rear view-oi the adjustable bridge used to support a switch box in the side wall of a building. Fig. 5 is a vertical cross section on the line of a.

The bridge comprises preferably a starnping in the form of straps a united at their ends by the cross bar portions 5 which are bent up their longitudinal centers to form flanges c which may be secured by nails or screws to the joists (5. These flanges form angle metal cross-bars. I

lt is preferable to make the bridge in the form or plur....ity of sets of straps which are intended to coincide one above the other, but which are adjustable lengthwlteby rea son. ofthe slots e and bolts and nuts Each outside pair of coinciding strapsis preterably provided with two pairs of slots, the in amidual members or which partially register as shown in the drawings. The central l of straps is, however, provided with only one pair of partially registering slots, which, however, are longer. This allows the fastening oi the ceiling or outlet box at any desired point along the bridge as the ceiling box 57 is secured the center pair of straps by bolts and nuts. lt is supported upon the outside pairs straps by reason of having bolted to it a cross Eterniing extensions which on top two outside pairs of straps and are slidable therealong to accord with new a 1 Specification of Letters Patent.

2 is a vertical section on the Fig. 3 is a vertical sible lire causes.

Patented Jan. this.

Serial No. 32,566.

made by the bolts and nuts to engage with the central pair of straps.

A metal wire conduit 2' is shown running into one side of the ceiling box, and a flexible conduit is shown running into the other side of the ceiling box 9. The metal conduit is fastened to the ceiling box by a pair of nuts 70, and the flexible conduitis fastened to the ceiling box 9 by a ring clamp Z.

The electric lamp chandelier is designated m and the thimble which covers the joint between the chandelier and the ceiling box is lettered n.

When my bridge is used to support an outlet box in the form of a switch box as shown in Figs. 4 and 5, the center pair of straps is omitted as it will be evident ithas not as great a bending strain upon the straps when the bridge is set up edgewise. lhe same adjustable features may be utilized in the side wall bridge as in the ceiling bridge by the employment of slots and bolts and nuts. However, it is preferable to employ only one set of slots for each pair of straps so that the switch box 0 may be adjustably securable to the outside pairs of straps by bolts and nuts 30 passed through the extensions on the switch box. The switch buttons 8 protrude through the face plate r.

llt has been quite customary heretofore to employ wooden blocks to support the lire tures and switch boxes from ceilings and walls respectively. These blocks have to be cut or titted to the particular spacing between the joists and inasmuch as the wooden blocks provide inflammable material about the ceiling box, it will be evident that the employment of a metal bridge such as l have described is an added protection pos- These bridges may be quickly and easily adjusted to any spacing employed between the joists or any irregularity in such spacings, and hence can be quickly and easily placed.

V1 hat ll claim is:

l. A bridge and outlet box of class described, having in combination, a pair of bridge portions each having at each end an angle metal cross-bar and each provided with a plurality of slotted straps integrally connected together by the metal crossbar, the straps of the two bridge portions adapted to be overlapped and secured selectable positions at overlap, and. an outlet box provided with extensions su ported on the outside straps in selectable ens.

2. A bridge and ceiling box of the class described, having in combination, a pair of bridge portions provided at their outside ends- With cross bars Which may be secured to the joists and having a plurality of slotted straps, the said straps of the two bridge portions being adapted to coincide, bolts and nuts for securing the bridge portions in various positions of adjustment by passing 10 through the'said slots, a ceiling box, bolts and nuts for securing the ceiling box at varying positions along the center pair of coinciding straps and passing through the s] obs in the same, and a cross strip secured to the top of the ceiling box and resting at each end on the outside pairs of straps.

In testimony whereof, I sigr. this specification.

JOHN R. GUNN. 

